OPCIT
| Date | Clue |
|---|---|
| 2021-10-03 | Footnote abbr. |
| 2020-03-28 | Endnote abbr. |
| 2018-01-10 | Footnote abbr. |
| 2017-09-24 | Footnote abbr. |
| 2017-01-14 | Cousin of ibid. |
| 2016-03-20 | Relative of ibid. |
| 2014-02-23 | Footnote abbr. |
| 2010-10-21 | Footnote abbr. |
| 2008-01-26 | Ibid. relative |
| 2008-01-10 | Footnote abbr. |
| 2004-03-18 | Footnote abbr. |
| 2001-06-21 | Ibid. relative |
| 2000-07-07 | Bibliographical abbr. |
| 1999-06-02 | Bibliography abbr. |
| 1999-01-20 | Footnote abbr. |
| 1997-04-26 | Footnote abbr. |